As far as a new character or story line about a POC, I think a deft writer could absolutely do it, especially if they took more creative licensing in rewriting the plot for television/streaming. Julia Quinn's writing is quite fanciful and light. It never really tackles heavy subjects, but in its reimagining and if we were to make it more realistic, they really could have come up with something, even if it were to make a maid a POC (which is more realistic for the time period) and handled it there, etc. There are a lot of possibilities but they never explored it. Outlander is more grisly but by far more accurate to its source time period.